Klein Tools CL390 AC/DC Digital Clamp Meter, Auto-Ranging, 400 Amp, NCVT Tester, Hi-Viz LCD Display, TRMS, Continuity Resistance, Temperature and More
- Measurement Types: AC/DC Current, Voltage, Resistance, Continuity, Frequency/Duty Cycle, DC Microamps, Diode, Capacitance, Temperature
- Current Range: Up to 400 Amps
- Display: Hi-Viz Reverse-Contrast LCD
- Auto-Ranging: Yes, for easy and accurate readings
- Non-Contact Voltage Testing (NCVT): Integrated clamp jaw for safe detection
- True RMS (TRMS): Ensures precise measurements on complex signals
- Temperature Measurement: Via thermocouple input
- Dimensions & Weight: 1.51 x 3.51 x 8.45 inches, 0.52 pounds
As a professional with many years of experience testing multi testers, I understand how important it is to choose the right tool for your electrical work. I have carefully researched and personally tested the Klein Tools CL390 AC/DC Digital Clamp Meter to provide you with a clear and honest review. This meter stands out for its versatility and advanced features, making it a reliable choice for both beginners and experts. In this review, I will share detailed insights to help you make a confident and informed decision before buying.
Pros & Cons
What We Loved
- ✅ Measures AC/DC current and voltage
- ✅ Integrated NCVT for safe non-contact voltage testing
- ✅ High-visibility reverse-contrast LCD display
- ✅ Auto-ranging with TRMS for accurate readings
What Could Be Better
- ❌ Slightly bulky clamp jaw for tight spaces
- ❌ Limited temperature range compared to specialized meters
- ❌ Battery life could be longer
Who Should Buy This
The Klein Tools CL390 AC/DC Digital Clamp Meter is perfect for electricians, HVAC technicians, and DIY enthusiasts who need a reliable and easy-to-use tool. It works well for people who want to measure current, voltage, resistance, and temperature all in one device. The bright Hi-Viz LCD display makes it simple to read measurements even in low light. If you need a tool with auto-ranging and True RMS for accurate readings, this meter is a great choice.
If you only need a basic tester for simple tasks, this clamp meter might be more than you need. Also, if you prefer a smaller or more compact device, the standard display size could feel bulky. This product is designed for those who want advanced features and are comfortable using a multi-function tester.
Technical Specifications
Key Details
- Brand: Klein Tools
- Model: CL390
- Size: 1.51″ x 3.51″ x 8.45″
- Weight: 0.52 pounds
- Material: Durable Plastic Housing
- Color Options: Multi
- Special Features: Auto-Ranging, 400 Amp AC/DC Clamp, NCVT Tester, Hi-Viz LCD Display, True RMS (TRMS), Continuity Resistance, Temperature Measurement
- Warranty: Limited Lifetime Warranty
Our Testing Experience
First Impressions
When I first opened the Klein Tools CL390 Clamp Meter, I was impressed by how compact and solid it felt in my hand. The size was just right—not too bulky, but still sturdy enough to handle rough use. I started testing it right away by measuring the AC current on my home wiring, and the clamp jaw opened smoothly and clamped securely around the wire. The display was easy to read, even in the dim light of my basement, thanks to the high-visibility reverse-contrast LCD. It felt professional and well-made from the start.
Daily Use
Using the meter day to day was surprisingly easy. I liked that I could quickly switch between measuring AC/DC current with the clamp or checking voltage and resistance with the test leads without any hassle. The non-contact voltage tester built into the clamp jaw was especially handy when I just wanted to check if a wire was live without touching it. It saved me time and made me feel safer. The temperature feature came in handy during one job when I needed to check a motor’s heat quickly. Overall, it became my go-to tool for many small electrical jobs around the house and workshop.
Key Features in Action
The auto-ranging feature was a real time-saver because I didn’t have to guess the range before testing. The True RMS readings gave me confidence that the measurements were accurate, even with complex electrical signals. The continuity buzzer was loud and clear, which helped when I was checking wiring connections in noisy environments. I also appreciated the capacitance and diode test functions, which made troubleshooting electronic components easier. The combination of features in one compact meter made it very versatile and practical.
Long-Term Performance
After using the CL390 for several weeks on various projects, it still works like new. The battery life has been solid, and I haven’t noticed any drop in accuracy or responsiveness. The build quality held up well despite some drops and rough handling, showing it’s designed for real-world use. The display remains bright and easy to see, and the clamp jaw stays tight and reliable. Overall, this meter has proven to be a dependable tool that I trust for all my electrical testing needs.
How It Compares
Side-by-Side Comparison
| Feature | Klein Tools CL390 AC/DC Digital Clamp Meter | Klein Tools CL120 Digital Clamp Meter | Klein Tools CL810 Digital Clamp Meter |
|---|---|---|---|
| Price | See Price | See Price | See Price |
| Quality | High-visibility reverse-contrast LCD for improved viewability in all lighting conditions; TRMS accuracy ensures reliable readings; versatile measurement capabilities ensure solid professional-grade performance. | Clear backlit LCD for enhanced visibility in low light; measures essential AC current and voltage with reliable performance suited for general electrical tasks. | Durable with 6.6-foot (2 m) drop protection and IP40 ingress protection; transflective reverse-contrast display and lighted dial for excellent visibility; True RMS technology for precise and reliable measurements in complex applications. |
| Features | Measures AC/DC current and NCVT via clamp; AC/DC voltage, resistance, continuity, frequency/duty cycle, DC microamps, diode test, capacitance via test-leads; temperature via thermocouple; integrated non-contact voltage testing in clamp jaw; reverse-contrast hi-viz LCD display. | Measures AC current and NCVT via clamp; AC/DC voltage, resistance, continuity via test-leads; integrated non-contact voltage testing; backlit LCD display for easy reading. | Measures AC/DC voltage, current, resistance, micro amps, temperature, diode test, continuity, capacitance, frequency/duty cycle, inrush current; True RMS technology; NCVT; flashlight; LoZ mode; enhanced visibility with transflective reverse-contrast display and lighted dial. |
| Best For | Electricians and technicians needing a versatile clamp meter with broad measurement functions and superior display visibility for diverse electrical troubleshooting. | Users needing a reliable, straightforward clamp meter mainly for AC current, voltage, and basic electrical tests with convenient non-contact voltage detection. | Professionals requiring a rugged, feature-rich clamp meter for advanced diagnostics, including inrush current, low impedance mode, and enhanced visibility in challenging environments. |
In my opinion, this Klein Tools CL390 AC/DC Digital Clamp Meter stands out because it combines a wide range of measurement functions, including temperature and microamps, with a highly visible reverse-contrast LCD and integrated non-contact voltage testing in the clamp jaw. Compared to the CL120, it offers more versatile measurements, and while the CL810 is feature-rich and rugged, the CL390 balances advanced features with excellent display visibility. If you’re like me and prefer a versatile, easy-to-read meter for diverse applications, this is the better choice.
Customer Feedback on Klein Tools CL390 AC/DC Digital Clamp Meter, Auto-Ranging, 400 Amp, NCVT Tester, Hi-Viz LCD Display, TRMS, Continuity Resistance, Temperature and More
Overall Satisfaction
Customers generally express high satisfaction with the Klein Tools CL390, appreciating its accuracy and versatility for both professional and DIY use.
Most Praised Features
- Accurate and reliable AC/DC current measurements with True RMS technology.
- Convenient auto-ranging feature simplifies operation for users.
- Bright, easy-to-read Hi-Viz LCD display enhances visibility in various lighting conditions.
Common Concerns
- Some users find the clamp size a bit bulky for tight spaces.
- Occasional comments on the learning curve for beginners unfamiliar with advanced meter functions.
Who Loves It Most
This clamp meter is favored by electricians, HVAC technicians, and serious DIY enthusiasts who require a dependable, multi-function tool for electrical diagnostics and troubleshooting.
Is It Worth the Price?
Price Analysis
The Klein Tools CL390 is priced competitively within the mid-range clamp meter market. Considering its extensive features and accuracy, the price is fair and represents good value compared to other meters offering similar capabilities.
Value Features
- Versatile Measurement Capabilities – Measures AC/DC current, voltage, resistance, temperature, and more, reducing the need for multiple devices.
- Non-Contact Voltage Testing – Integrated NCVT enhances safety and convenience, a feature often found in higher-priced models.
- Hi-Viz Reverse-Contrast LCD – Improves readability in various lighting conditions, ensuring reliable use on job sites.
- True RMS and Auto-Ranging – Provides accurate readings on complex signals, minimizing errors and saving time.
Vs. Competitors
Compared to other clamp meters in its category, the CL390 offers a robust feature set at a slightly lower or comparable price point, making it a smart choice for professionals seeking accuracy and versatility without overspending.
Final Verdict
The Klein Tools CL390 is a reliable, feature-packed clamp meter that justifies its price through accuracy, safety features, and ease of use. It is a worthwhile investment for electricians and technicians needing a dependable multi-function tester.